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Commit cecf8a69 authored by Srinivas Kandagatla's avatar Srinivas Kandagatla Committed by Greg Kroah-Hartman
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dmaengine: qcom: bam_dma: get num-channels and num-ees from dt 



[ Upstream commit 48d163b1aa6e7f650c0b7a4f9c61c387a6def868 ]

When Linux is master of BAM, it can directly read registers to know number
of supported channels, however when its remotely controlled reading these
registers would trigger a crash if the BAM is not yet initialized or
powered up on the remote side.

This patch allows driver to read num-channels and num-ees from Device Tree
for remotely controlled BAM.

Signed-off-by: default avatarSrinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: default avatarVinod Koul <vinod.koul@intel.com>
Signed-off-by: default avatarSasha Levin <alexander.levin@microsoft.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 086a52f1

drivers/dma/qcom/bam_dma.c

+22 −5
Original line number Original line Diff line number Diff line
@@ -387,6 +387,7 @@ struct bam_device { 
	struct device_dma_parameters dma_parms;

	struct device_dma_parameters dma_parms;

	struct bam_chan *channels;

	struct bam_chan *channels;

	u32 num_channels;

	u32 num_channels;

	u32 num_ees;





	/* execution environment ID, from DT */

	/* execution environment ID, from DT */

	u32 ee;

	u32 ee;
@@ -1076,15 +1077,19 @@ static int bam_init(struct bam_device *bdev) 
	u32 val;

	u32 val;





	/* read revision and configuration information */

	/* read revision and configuration information */

	val = readl_relaxed(bam_addr(bdev, 0, BAM_REVISION)) >> NUM_EES_SHIFT;

	if (!bdev->num_ees) {

	val &= NUM_EES_MASK;

		val = readl_relaxed(bam_addr(bdev, 0, BAM_REVISION));

		bdev->num_ees = (val >> NUM_EES_SHIFT) & NUM_EES_MASK;

	}





	/* check that configured EE is within range */

	/* check that configured EE is within range */

	if (bdev->ee >= val)

	if (bdev->ee >= bdev->num_ees)

		return -EINVAL;

		return -EINVAL;





	if (!bdev->num_channels) {

		val = readl_relaxed(bam_addr(bdev, 0, BAM_NUM_PIPES));

		val = readl_relaxed(bam_addr(bdev, 0, BAM_NUM_PIPES));

		bdev->num_channels = val & BAM_NUM_PIPES_MASK;

		bdev->num_channels = val & BAM_NUM_PIPES_MASK;

	}





	if (bdev->controlled_remotely)

	if (bdev->controlled_remotely)

		return 0;

		return 0;
@@ -1179,6 +1184,18 @@ static int bam_dma_probe(struct platform_device *pdev) 
	bdev->controlled_remotely = of_property_read_bool(pdev->dev.of_node,

	bdev->controlled_remotely = of_property_read_bool(pdev->dev.of_node,

						"qcom,controlled-remotely");

						"qcom,controlled-remotely");





	if (bdev->controlled_remotely) {

		ret = of_property_read_u32(pdev->dev.of_node, "num-channels",

					   &bdev->num_channels);

		if (ret)

			dev_err(bdev->dev, "num-channels unspecified in dt\n");



		ret = of_property_read_u32(pdev->dev.of_node, "qcom,num-ees",

					   &bdev->num_ees);

		if (ret)

			dev_err(bdev->dev, "num-ees unspecified in dt\n");

	}



	bdev->bamclk = devm_clk_get(bdev->dev, "bam_clk");

	bdev->bamclk = devm_clk_get(bdev->dev, "bam_clk");

	if (IS_ERR(bdev->bamclk))

	if (IS_ERR(bdev->bamclk))

		return PTR_ERR(bdev->bamclk);

		return PTR_ERR(bdev->bamclk);